Drive for the stepped drums of calculating machines



A. KOTTMANN DRIVE FOR THE STEPPED DRUMS OF CALCULATIIG MACHINES Filed Nov. 23. 1926 2 Sheets-Sheet l NN mu QN. Q

IWENTDQ mgmt Ittmann Dec. 23, 1930 Wmv@ A. Ko'rTMANN 1,786,164

DRIVE FOR THE STEPPED DRUMS OF CALCULATING MACHINES Dec. 23, 1930 Filed Nov. 23, 1926 2 Sheets-Sheet 2 @45t-orme M. v@ ,N

- stepped drum is dependent upon Patented Dec. 23, 1930 UNITED STATES PATENT OFFICE AUGUST KOTTMANN, OF SOMMERDA, GERMANY, ASSIGNOR T0 TEE FIRM RHEINISGHE METALLWAAREN 'UND MASCHINENFABRIK SMMERDA OF SOMMERDA, GERMANY AKTIENGESELLSCHAFT,

DRIVE FOR THE STEPPED DRUMS OF CALCULATING MACHINES Application led November 23, 1926, Serial No. 150,331, and in Germany December 10, 1925.

In known drives for the stepped drums of calculating machines usually a stepped drum is arranged underneath each adjusting shaft. The number of divisions or pitches of a the number of places in the result mechanism, because in a calculating machine the tens transfer proceeds fromA the units lto the tens, then from the tens to the hundreds and so on. The tens transfer thus runs from right to left through the machine. For this reason it is necessary to divide the circumference of the stepped drum into so many pitches that in addition to the pitches for the stepped teeth (i. e. 9) there are also further present as many pitchesv for the tens transfer cams, which must become effective one after the other, as there are denominations having tens transfer mechanism. In addition it is customary to provide' two additional pitches which have no teeth, so that the stepped drums can be revolved through two pitches without adecting the computing mechanism in any way. This play is necessary to avoid error in case the driving crank is not returned exactly to the zero position at the conclusion of a calculation. According to a known construction for instance itis necessary, that each stepped drum be provided with nine teeth for inserting the numerals (from -l to 9) in that denomination in the machine, further with a tooth pitch for each .tens transfer mechanism, since the tens transfers occur one after the other and also with a tooth pitch for the play before and after the engagement. In a result mechanism for a range of 13 denominations for instance a stepped drum should be provided with the following number of tooth pitches: 9 pitches for the teeth for inserting the amounts, 12 pitches for the subsequent tens transfers and 2 pitches for the play, together 23 tooth pitches.

In order to prevent too small pitches, the diameter of the stepped drums and therefore lthe distance of the shafts of the drums from each other mustbe great, resulting in great and unhandy machines in which furthermore the sight openings of the counting mechanism are arranged at agreat distance from each other, so that difficulties arise in reading od the adjusted numbers. Many efforts have therefore been made to reduce these great distances and many different methods have been proposed to obtain this object in the best possible manner.

For instance stepped drum-calculating machines have become known in which the stepped drums are arranged in staggered relation. This, however, results in an enlargement of the size of the machine in the direction of the shafts of the stepped drums. Another known construction in which each stepped drum drives two denominations has the disadvantage that the parts are very large and when in motion, .tend to overthrow because of their great momentum. In these two constructions therefore the reduction of the distance of the shafts from each other without reducing the stepped drums has been obtained by a skillful arrangement of the drums only. In other Ways attempts have been made to reduce as far as possible the diameter of the stepped drums.

In a calculating machine of the last mentioned construction the stepped drums are so driven, that always the drum arranged more to the left is rotated only when the neighbouring drum to the right has been stopped. Hereby the compass of the stepped drums is reduced to the smallest amount possible of l0 pitches only, but this machine has the disadvantage, that the toothed segments driving the several stepped drums become very great, as they must be cut from toothed wheels which for a machine of 13 denominations for instance have 13 10:130 teeth.

Moreover a stepped wheel calculating machineis known in which the upper denominations driven by the tens transfer cams only are separated and driven separately, whereby the compass of the stepped wheels is reduced for so many tooth pitches as denominations are separated. This method may be transferred to stepped drum machines and would reduce the compass of the stepped drums in the same measure.

According to the present invention the disthe two last mentioned systems, reduced by a reduction of the diameter of the drum, whereby, however, a considerably greater reduction of the compass and diameter of thev drums is obtained as in the second of the lwo systems While at the same time the great toothed segments of the first of the two systems are obviated.

In case the upper denominations driven only by tens transfer cams are sepa-rated, the above mentioned object is obtained, according to the invention, by also subdividing the stepped drums into groups which are driven one after the other. Hereby, however, the one group of stepped drums is not only then rotated when the neighbouring group to the right has been stopped but the group arranged further to the left lags the neighbouring group to the right only for so many tooth pitches as the group arranged to the right has tens transfer cams. The group arranged to the right therefore is stopped only when the drums of the group arranged to the left have been rotated already for 9 teeth. p

If the upper denominations driven by tens transfer cams are separated, the separated tens transfer cams also may be subdivided in groups which are driven one after the other. If the upper denominations are not separated the whole driving means present must be subdivided into groups in such a manner, that one of these groups contains denominations driven by tens transfer cams only as well as denominations driven by stepped drums and tens transfer cams.

According to a modification of theinvention each group of stepped drums and each group of tens transfer cams consist of one'unit (stepped drum, tens transfer cam) so that the driving shafts for the groups may be omitted. The main drive shaft in this case extends, as in the usual bevel gear drive for stepped drums, through the whole machine and directly drives, by means of bevel gear segments, the several groups (in the present case it can also be said the several single stepped drums).

shaft in such a manner that always the one arranged to the left lags the neighbouring one to the right for 011e tooth pitch. These bevel individual stepped drums) make one revolution at each revolution of the main drive shaft.

In the accompanying drawings in which the same reference numbers are used in the several views to designate equivalent parts two modes of carrying out the invention areshown diagrammatically by way of example. In these drawings:

Fig. 1 is a view showing the arrangement The se bevel gear segments are all of the same construction, but fixed to the* of the stepped drums, the tens teeth and the adjusting shafts arranged thereabove,

Fig. 2 shows the drive arrangement for the stepped drums,

Fig. 3 is a top plan View thereof,

Fig. 4 is a side elevation of the crank and the two drive shafts for the stepped drums,

Fig. 5 is an elevation of a modified drive for the stepped drums,

Fig. 6 is a top plan view of the drive shown in Fig. 5 and Figs. 7-12 are detail views showing the relative positions of the bevel gear segments.

In the construction illustrated in Figs. 1-4 the drive shafts 4, 5 and 6 are arranged in bearings 2. and 3 at the front wall 1 of the calculating machine. Mounted upon the shafts 5 and 6 are the bevel gear Wheels 7 which extend through the wall 1 and engage the` bevel gear wheels 8. The bevel gear wheels 8 are fixed upon the shafts 9 of the stepped drums l0 which also carry. the sectors 11 provided with the tens teeth 12. In holes 13 in the front wall 1 are journalled square shafts 14 upon which are arranged the adjusting wheels l5 and the tens sleeves provided with the star discs 16. The shaft 5 belonging to the first group of stepped drums and the auxiliary shaft 4 respectively carry the gears 17 and 18 which are driven by the toothed sectors 19 mounted upon the shaft 20 of the crank 21. Overthrow is prevented, in well known manner, by sectors 22 and cam discs 23. The shaft 6 belonging to the second group of stepped drums is driven from the auxiliary shaft 4 by means of the gears 24 and 25. As shown in the drawings the shafts 5 and 6 do not form a single continuous axle, but are made of two separate pieces abutting against each other in the bearing 2.

Preferably but not necessarily the groups are so divided that if possible each group contains the same number of stepped drums (more exactly tens transfer cams). In the drawings only one of the groups of stepped drums is shown completely, the left hand group being broken away at the left hand side. For the purpose of further descrip tion it may be assumed that the machine has 13 denominations in the result counting mechanism three of which only are driven by tens transfer cams. As the right hand group contains 7 stepped drums, the left hand group in fact drives 6 denominations and of these 3 only are driven by the tens transfer cams.

The stepped drums of the right hand group have a compass of 17 pitches, one pitch each for play before and after engagement of the drums, 9 pitches for the teeth of the stepped drumand 6 pitches for the tens transfer (the lowermost denomination has no tens transfer tooth). The bevel gear wheels 7 and 8 and the gear 17 have the same number of teeth.

' to the The stepped drums of the left hand group (it contains in fact 3 stepped drums and 3 tens transfer teeth, whereas the drawing shows only one stepped drum) also have a compass of 2+9+6=17 pitches. Accordingly in this group the bevel gear wheels 7 and 8 and the gears 24:, 25 and 18 also have 17 teeth. Therefore the toothed segments 19 of the main drive shaft must also have 17 teeth, if for each revolution of the main drive shaft 2() the shafts 4, 5 and 6 are to make also one revolution. If now the segments are made from complete gears having 2+9+12=23 teeth and these segments are arranged in staggered relation in such a manner that the segment driving the left hand group lags the segment driving the right hand group for 6 teeth, the tens transfer in the several denominationsis (as will be shown in the following description) eected progressively and successively from the right left, that is to say in the manner required.

If the main drive shaftv 20 is turned by means of the crank 21 for one revolution it first of all freely turns one for tooth pitch as one pitch is provided for play. Then `the first tooth of the toothed segment 19 driving the right hand group engages with the gear 17, so that now the stepped drums (which in the groups are in well known manner so arranged, that always the one arranged to the right leads for one tooth pitch the neighbouring drum arranged to the left) are rotated. -After the 'whole segment has passed the gear 17, the stepped drums (which just now have made one revolution) are stopped. The tens transfer is effected by the tens transfer cam of the highest denomination of the group in the very moment in which -the last but one tooth of the segment 19 engages the gear 17 (because on the stepped drums also after engagement one pitch is provided for play).

The left hand group starts after the right hand group has turned for 6 pitches (the segments 19 are staggered for 6 pitches). As the tens transfer tooth of the highest denomination of the right hand group effects the tens transfer after the stepped drums have turned for 1 9 6== 16 pitches, the left hand group has already turned for 16-6=10 pitches in the moment in4 which the tens transfer is active i'n the highest denomination of the right hand group. As in the left hand group also a pitchf` for play before engagement was provided the ninth stepped tooth isA just in engagement. Only when the stepped drum turns further for one pitch, does the tens ltransfer cam come into engagement. 'Ihe tens transfer is therefore also continuously effected beyond the separating point, although in the moment in which the 'right hand group is stopped the left hand group has already turned for 10 teeth.

If the calculating machine has altogether lml tens transfers and if the several groups contain n tenstransfers, the tens transfer of the whole machine Works satisfactorily, if the stepped drums 10, the bevel gear wheels 7 and 8, the gears 17, 18, 24 and 25 and the segments 19 have (Qd-9+@ teeth, if at the same .time the toothed segments are made from complete gears the compass of which contains (2+9-i-m) ments are staggered for n pitches.

In theexample shown in Figs. 1 4 all the stepped drums and tens transfer cams are subdivided into two groups only which has been done forthe purpose of simplicity only. rlhe advantages of the invention are still more emphasized with a subdivision in more groups, because the compass of the stepped drums is (2+9-i-n) pitches. lVith a given pitch the compass and diameter of the stepped drums become the smaller, the smaller the number n, becomes of the stepped drums contained in the several groups. The proportions are most favorable if each group contains only one stepped drum, that is to say, if the number of groups is equal to the number of denominations of the machine.

lf the stepped drums and tens transfer cams are subdivided into more than two groups, the number of the driving segments upon the driving shaft must be augmented to correspond to the number of groups, and 'for each group the intermediate transfer members cooperating withthe associated toothed sectors upon the drive shaft must be provided.

In the modification shown in Figs. 5-12 the driving shaft 5 is also journalled at the front wall 'l of the machine in bearings 2 and 3. The shaft 5 carries the bevel ear wheel segments 7 1-7 which are keye in pitches and if the seg-"- staggered relation in sucha manner, that always the left hand segment lags the rightv hand segment for one pitch, except the two segments 71 and 72'arranged to the extreme right whichl are not staggered relative to each other, because the lowermost denomination of the calculating machine has no tens transfer cam.

As mentioned above in connection with the first example, the stepped drums as Well as the tens transfer cams of the upper denominations of the counting mechanism which are not driven by stepped drums may be driven in groups. The definitions stepped drum and group of stepped drums7 therefore coincide. For this reason in the following description there will be no longer any reference `made to groups of stepped drums; but simply to stepped drums also no longer to groups of tens transfer cams but only to tens transfer cams.

The 4main drive shaft 5 lies close in front of the ends of the stepped drum shafts 9, the bevel gear wheel segments of the main drive shaft 5 extend through the wall 1 and engage with the bevel gear Wheels 8. The bevel gear wheels 8 are fixed to the shafts 9 which carry also the tens transfer cams, or, in the upper denominations of the count-ing mechanism, the tens transfer cams only. A

The compass of the stepped drums is 12 pitches, 9 pitches for the stepped teeth, one pitch for the tens transfer camand onepitch each for play before and after engagement with the adJusting wheel. The bevel gear wheels 8 of the shafts 9 as well as the bevel gear wheel segments 71-7 of the main drive shaft have 12 teeth. Y

v If all the stepped drums were to start simultaneously, the tens transfer cams of all denominations would act simultaneously. AS this is not admissible, the arrangement is such that always the stepped drum situated at the left hand side lags for one pitch the neighbouring drum arranged to the right. This is obt-ained by the already described staggered arrangement of the bevel gear wheelv segments 72- 6 of the main drive shaft 5.

For machines having n denominations the bevel gear wheel segments are parts of complete bevel gear wheels of a compass of 12+ (7L-1) pitches, 12 pitches for the teeth engaging with the teeth of wheels 8 a-nd (n-1) pitches as play for t-he (7l/*1) tens transfers. For the machine shown by Way of example in Figs. 5-12 the segments therefore are parts of complete bevel gear wheels having a compass of 12+ (t3-1) =17 pitches (a play before and after engagement was already provided at the stepped drums and need therefore not to be provided again).

If now the shaft 5 is rotated from the zero posit-ion, the bevel gear wheel segments 71 and 72 come first into engagement with the bevel gear wheels 8 of the two lowermost denominations. If these wheels have been turned for one pitch the bevel gear wheel segment 7 3 also comes into engagement and after rotation for a. further pitch also the segment 7 4 and so on. The stepped drum situated'at the left hand side together with the associated tens transfercam therefore always lags the neighbouring drum arranged to the right for one pitch. The tens transfer teeth therefore come into engagement one after the other in the same succession. |The tens transfer is therefore actuated as required from the right to the left through the several denominations of the machine although thestepped drums have the small compass of only 12 pitches.

The advantage of this modification with regard to the firstdescribed construction is to be seen on the one hand in this, that the compass of the stepped drums has the small est possible value and on the other hand that the drive is considerably simplified as all group driving shafts and intermediate shafts are dispensedwith.

, Calculating machines are already known in which the stepped drums are driven in such a manner that always the stepped drum arranged at the left hand side is started only when the neighbouring drum situated at the right hand side has been stopped. These machines have the disadvantage that the bevel gear wheel segments of the main drive shaft reach very great dimensions, i. e. such great dimensions, that it is impossible to arrange the main drive shaft close in front of the ends of the stepped drums. In these machines, therefore, the main drive shaft is arranged in a lower plane and connected to the stepped drums 9 by means of intermediate bevelgear wheels. Also with regardto such machines the drive according to the present invention is to be considered as a substantial simplification as much smaller segments are required and the intermediate bevel gear is dispensed with.

What I claim is:

1. In a drive for the stepped drums of calculating machines in combination, a constantly rotated main drive shaft, means for moving through said shaft successively in groups the stepped drums in several groups in such a mannerthat always the group arranged further to the left lags the preceding one for so manytooth pitches as this latter group contains tens transfer teeth, groups of tens transfer cams for driving the upper denominations of the counting mechanism, and means for successively. starting these tens transfer cams in groups.

2. In a drive for the stepped drums of calculating machines, in combination, groups of stepped drums and groups of tens transfer mechanism associated therewith, a drive shaft associated with each of said groups of drums, gear wheels mounted on said drive shafts for driving the several groups of drums and transfer mechanisms, and means for driving said shafts in such timed relation that always the Group arranged at the left hand side lags tIie neighbouring group to the right by as many tooth pitches as the latter has tens transfer mechanisms.

3. In a calculating machine, the combination of a plurality of stepped drums, tens transfer mechanism for at least some of said drums, a rotatable drive shaft, and drive connections between said drive shaft and the drums for rotating the latter, the drive connections being in such phase relation to each other that each drum will lag the drums of lower denomination for so many tooth pitches as such last-mentioned drums contain tens transfer teeth.

4. In a calculating machine, the combination of a plurality of stepped drums, said drums being arranged in a plurality of groups, each of said drums corresponding to a denomination in the result mechanism and each group' comprising a plurality of such drums, a drive shaft, and driving connections between said shaft andsaidgroups of drums,l

said driving connections having idle motion relatively to each other whereby said groups are actuated in out-of-phase relation, one of said groups being provided with denominations which are driven by tens transfer cams only, as Well as with denominations which are driven by both tens transfer cams and stepped drums.

In testimony whereof I have aixed my signature.

AUGUST KOTTMANN. 

